Existing starting, lighting and ignition (SLI) batteries of the type commonly used to start the internal combustion engines of cars, trucks, motorcycles, lawn and garden equipment and the like are large, heavy, flooded electrolyte type lead-acid batteries. These batteries consist almost exclusively of a prismatic container into which a number of partitions are formed in order to define cells. Stacks of electrodes, made from interleaved positive and negative plates and separator material, are inserted into the cells and are electrically interconnected and connected with either top or side terminal mounts. The plates are typically lead or lead alloy grids covered with an active material such as lead dioxide. The cells are flooded with electrolyte, usually a dilute sulfuric acid solution, and a cover is heat sealed to the container. Vents are provided in the cover to allow for the venting of gases generated during the normal discharge and recharge cycles.
A typical SLI battery can weigh as much as twenty (20) kilograms. The construction also requires careful top-up mounting to avoid spillage of electrolyte. Because of its size, the use of liquid electrolyte, venting and other concerns, the SLI battery has typically been mounted within the engine compartment of cars and trucks. However, it is known that battery life is adversely affected by heat and vibration so the engine compartment is actually an undesirable location. In addition, the size, weight, liquid electrolyte and gassing makes replacing worn or discharged batteries a task best left to a skilled mechanic. Jump starting a vehicle when the battery is discharged poses certain problems, and requires a second vehicle or energy source.
Thin metal film battery technology provides in a compact design a high power battery cell. Cells of this type are well known and their construction and manufacture have been described in, for example, U.S. Pat. Nos. 3,494,800; 5,045,086; 5,047,300; 5,198,313 and 5,368,961 the disclosures of which are hereby expressly incorporated herein by reference. A thin metal film battery cell includes thin metal film plates sealed within a sealed cell container which is valve regulated. The cells include absorptive glass-mat (AGM) separator technology in an electrolyte starved system. The thin metal film plates are made from very thin lead foil approximately about 0.005 inches thick, pasted with an active material forming a pasted plate approximately about 0.012 inches thick. The plates are spiral wound with separator material, and terminations are cast-on or soldered to the ends of the spiral roll. The roll is encapsulated in a container which is filled with electrolyte and then sealed except for the vent. The performance characteristics of thin metal film cells include a high power weight ratio and rapid recharge capability.
In spite of the existence of alternate cell technology, the typical SLI battery remains a large, heavy, flooded electrolyte battery. Such SLI battery construction has left little flexibility to the car, truck or other product designer in packaging and protecting the SLI battery. Cars and trucks still find large, heavy SLI batteries located in the harsh under-hood environment.
In certain instances which can not be totally avoided, the SLI battery may become discharged such that it can not provide sufficient energy to start the engine of the car, truck or other product. The common response to this problem is to couple a second energy source, such as the electrical system of a second vehicle or a specially designed jump starting energy source, to the SLI battery. When coupled, the second energy source provides the energy to start the engine, and once running, the engine is capable of providing energy through a suitable charging system for recharging the discharged SLI battery. However, one must be careful to properly couple the energy sources. Failing to do so can lead to serious damage to the electrical system of the vehicle, the SLI battery and the second energy source. In the discharged battery situation, with a typical SLI battery it is highly impractical but would be very desirable to simply remove the discharged battery and replace it with another battery having sufficient charge to start the engine. Unfortunately, however, the typical large, heavy SLI battery is not readily removed or uncoupled from the vehicle. And, without a second energy source, the vehicle operator will be stranded.